There's basically two ways that I can see the whole "re-tweet my straight edge message" situation playing out.

One is, as you have said, an example of someone trying to get attention. I agree that in most cases, this is pretty narcissistic and defeats any redeeming purpose. As such, the individual's motivation would primarily be to receive praise.

However, I have heard frequently that if you are trying to kick some bad habit or reach some goal, you are more likely to succeed if you share it with people you know. This creates a support group of sorts that you do not want to let down - partly for fear of embarrassment, but perhaps mostly because there is something that must be altered for a positive outcome.

I don't follow the Magic world at all; I'm not sure who the individual is, or whether or not their motivation lies in cashing in on some praise or to genuinely become straight edge. I generally agree that the use of Twitter to broadcast this message, as well as requesting people to re-tweet the message, seems to go a bit far for little impact. As such, the situation at hand does appear to be quite praise-oriented - and praise alone doesn't frequently solve problems.

Still, if someone you know very well mentions to you that they're trying to reform in some way - for example, quitting smoking or such - you should support that person because you have effectively become part of that role. I guess you don't have to necessarily praise them if the change hasn't occurred yet, but a little positiveness never killed anyone either.